In recent years, methodological advances have provided researchers with improved techniques to model and study longitudinal data. The purpose of the proposed research is to apply growth mixture modeling (GMM), one of these new techniques, to the landmark, NIMH-funded Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study. The CATIE study includes data on 1,460 adults with schizophrenia. Interviews were conducted every 90 days over the course of 18 months. The proposed study will utilize GMM to: (a) describe the growth trajectories for substance use in persons with schizophrenia;(b) relate these growth trajectories of change to clinically and theoretically relevant variables, including medication and outpatient services;and (c) determine if different latent substance use classes have different outcomes, including those related to violence, victimization, psychosis, depression, and quality of life. Results from this study should provide substantive knowledge to behavioral health services practitioners about which classes of participants benefit from various treatments. The application requests two years of supplemental SOAR research support for Drs. Richard A. Van Dorn (Principal Investigator: University of South Florida), M. Scott Young and Beom Lee (Co-Investigators: University of South Florida). The proposed project will expand the clinical, empirical, and theoretical literature relating to substance use in persons with schizophrenia. Outcomes associated with the proposed project have the potential to yield significant public health and clinical benefits for this at-risk population. In this context, persons with schizophrenia are a vulnerable population that evinces complex clinical profiles, which increases risks for substance use and other negative outcomes at higher rates than are present in people with other mental illnesses or members of the general public. PUBLIC HEALTH RELEVANCE: Outcomes from this project will have important implications for improving detection and clinical practice to help reduce or prevent substance use for persons with schizophrenia. Substance use in this population represents a significant public health concern as the prevalence is significantly higher in persons with schizophrenia compared to rates found with other mental illnesses or in the general population.